OPINION

Rethinking Sleep

By DAVID K. RANDALL

SOMETIME in the dark stretch of the night it happens. Perhaps it’s the chime of an incoming text message. Or your iPhone screen lights up to alert you to a new e-mail. Or you find yourself staring at the ceiling, replaying the day in your head. Next thing you know, you’re out of bed and engaged with the world, once again ignoring the often quoted fact that eight straight hours of sleep is essential.

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Sound familiar? You’re not alone. Thanks in part to technology and its constant pinging and chiming, roughly 41 million people in the United States — nearly a third of all working adults — get six hours or fewer of sleep a night, according to a recent report from the Centers for Disease Control and Prevention. And sleep deprivation is an affliction that crosses economic lines. About 42 percent of workers in the mining industry are sleep-deprived, while about 27 percent of financial or insurance industry workers share the same complaint.

Typically, mention of our ever increasing sleeplessness is followed by calls for earlier bedtimes and a longer night’s sleep. But this directive may be part of the problem. Rather than helping us to get more rest, the tyranny of the eight-hour block reinforces a narrow conception of sleep and how we should approach it. Some of the time we spend tossing and turning may even result from misconceptions about sleep and our bodily needs: in fact neither our bodies nor our brains are built for the roughly one-third of our lives that we spend in bed.

The idea that we should sleep in eight-hour chunks is relatively recent. The world’s population sleeps in various and surprising ways. Millions of Chinese workers continue to put their heads on their desks for a nap of an hour or so after lunch, for example, and daytime napping is common from India to Spain.

One of the first signs that the emphasis on a straight eight-hour sleep had outlived its usefulness arose in the early 1990s, thanks to a history professor at Virginia Tech named A. Roger Ekirch, who spent hours investigating the history of the night and began to notice strange references to sleep. A character in the “Canterbury Tales,” for instance, decides to go back to bed after her “firste sleep.” A doctor in England wrote that the time between the “first sleep” and the “second sleep” was the best time for study and reflection. And one 16th-century French physician concluded that laborers were able to conceive more children because they waited until after their “first sleep” to make love. Professor Ekirch soon learned that he wasn’t the only one who was on to the historical existence of alternate sleep cycles. In a fluke of history, Thomas A. Wehr, a psychiatrist then working at the National Institute of Mental Health in Bethesda, Md., was conducting an experiment in which subjects were deprived of artificial light. Without the illumination and distraction from light bulbs, televisions or computers, the subjects slept through the night, at least at first. But, after a while, Dr. Wehr noticed that subjects began to wake up a little after midnight, lie awake for a couple of hours, and then drift back to sleep again, in the same pattern of segmented sleep that Professor Ekirch saw referenced in historical records and early works of literature.

It seemed that, given a chance to be free of modern life, the body would naturally settle into a split sleep schedule. Subjects grew to like experiencing nighttime in a new way. Once they broke their conception of what form sleep should come in, they looked forward to the time in the middle of the night as a chance for deep thinking of all kinds, whether in the form of self-reflection, getting a jump on the next day or amorous activity. Most of us, however, do not treat middle-of-the-night awakenings as a sign of a normal, functioning brain.

Doctors who peddle sleep aid products and call for more sleep may unintentionally reinforce the idea that there is something wrong or off-kilter about interrupted sleep cycles. Sleep anxiety is a common result: we know we should be getting a good night’s rest but imagine we are doing something wrong if we awaken in the middle of the night. Related worries turn many of us into insomniacs and incite many to reach for sleeping pills or sleep aids, which reinforces a cycle that the Harvard psychologist Daniel M. Wegner has called “the ironic processes of mental control.”

As we lie in our beds thinking about the sleep we’re not getting, we diminish the chances of enjoying a peaceful night’s rest.

This, despite the fact that a number of recent studies suggest that any deep sleep — whether in an eight-hour block or a 30-minute nap — primes our brains to function at a higher level, letting us come up with better ideas, find solutions to puzzles more quickly, identify patterns faster and recall information more accurately. In a NASA-financed study, for example, a team of researchers led by David F. Dinges, a professor at the University of Pennsylvania, found that letting subjects nap for as little as 24 minutes improved their cognitive performance.

In another study conducted by Simon Durrant, a professor at the University of Lincoln, in England, the amount of time a subject spent in deep sleep during a nap predicted his or her later performance at recalling a short burst of melodic tones. And researchers at the City University of New York found that short naps helped subjects identify more literal and figurative connections between objects than those who simply stayed awake.

Robert Stickgold, a professor of psychiatry at Harvard Medical School, proposes that sleep — including short naps that include deep sleep — offers our brains the chance to decide what new information to keep and what to toss. That could be one reason our dreams are laden with strange plots and characters, a result of the brain’s trying to find connections between what it’s recently learned and what is stored in our long-term memory. Rapid eye movement sleep — so named because researchers who discovered this sleep stage were astonished to see the fluttering eyelids of sleeping subjects — is the only phase of sleep during which the brain is as active as it is when we are fully conscious, and seems to offer our brains the best chance to come up with new ideas and hone recently acquired skills. When we awaken, our minds are often better able to make connections that were hidden in the jumble of information.

Gradual acceptance of the notion that sequential sleep hours are not essential for high-level job performance has led to increased workplace tolerance for napping and other alternate daily schedules.

Employees at Google, for instance, are offered the chance to nap at work because the company believes it may increase productivity. Thomas Balkin, the head of the department of behavioral biology at the Walter Reed Army Institute of Research, imagines a near future in which military commanders can know how much total sleep an individual soldier has had over a 24-hour time frame thanks to wristwatch-size sleep monitors. After consulting computer models that predict how decision-making abilities decline with fatigue, a soldier could then be ordered to take a nap to prepare for an approaching mission. The cognitive benefit of a nap could last anywhere from one to three hours, depending on what stage of sleep a person reaches before awakening.

Most of us are not fortunate enough to work in office environments that permit, much less smile upon, on-the-job napping. But there are increasing suggestions that greater tolerance for altered sleep schedules might be in our collective interest. Researchers have observed, for example, that long-haul pilots who sleep during flights perform better when maneuvering aircraft through the critical stages of descent and landing.

Several Major League Baseball teams have adapted to the demands of a long season by changing their sleep patterns. Fernando Montes, the former strength and conditioning coach for the Texas Rangers, counseled his players to fall asleep with the curtains in their hotel rooms open so that they would naturally wake up at sunrise no matter what time zone they were in — even if it meant cutting into an eight-hour sleeping block. Once they arrived at the ballpark, Montes would set up a quiet area where they could sleep before the game. Players said that, thanks to this schedule, they felt great both physically and mentally over the long haul.

Strategic napping in the Rangers style could benefit us all. No one argues that sleep is not essential. But freeing ourselves from needlessly rigid and quite possibly outdated ideas about what constitutes a good night’s sleep might help put many of us to rest, in a healthy and productive, if not eight-hour long, block.

David K. Randall is a senior reporter at Reuters and the author of “Dreamland: Adventures in the Strange Science of Sleep.”

A version of this op-ed appeared in print on September 23, 2012, on page SR1 of the New York edition with the headline: Rethinking Sleep.

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185 Comments

As a new mom of a two month old that sleeps for one 5-6 hour chunk followed by a 30-45 min alert period and another 2-3 hour sleep, I feel surprisingly rested in the morning. So this idea of split sleep really resonates with me!

1) Though it might be our natural sleep cycle to have "two sleeps," our ancestors didn't have light in the middle of the night like we do, unless they all got up at the same time at night and built a fire. So I'm not sure how the reading, studying, watching TV, etc. in the middle of the night fits into this. Certainly that's not a restful as just laying there thinking or having sex.

2) Many people here are mentioning that a key to their happy sleeping lives is the ability to sleep anywhere and at any time. I think this is great, and I wish I had this skill. Unfortunately, I read a lot of parenting books (and I think I was raised this way, as well) where the author tells parents NEVER to let their child fall asleep anywhere but their own bed, and only during prescribed sleep times. How can children who are raised this way ever grow up to happily takes naps at their desk?

Another 'boomer', thinking outside the box again...when will we ever stop! Also have discovered the split sleep cycle in my 'retiring' years. I now prefer to sleep 5-6 hrs at night and a 1-2 hr nap in afternoon. I can be very alert at 4:10 pm and almost literally not able to stay awake (unless driving) at 4:15-4:19!! nearly every day. These 2 hr naps were initially so disturbing I consulted my doctor....thanks to this article and people sharing their own experience I can stop being concerned. I feel that this knowledge sharing is only going to get more interesting! Yayyy.

Good luck changing the military and the sleep patterns of Marines. They go for days without anything but a cat nap and the lack of sleep has contributed to PTSD. Our military in combat are "sleep deprived" and one must think about what this does to their judgment. The Seals on that plane were able to sleep probably because they were so tired they could not stay awake. I have looked into the eyes of Seals and Marines and can see what sleep deprivation has done to them.

This article fails to include a huge body of research on sleep performed by NIH and NIMH in the 21st century, as well as, other major research institutions. Anecdotal stories of sleep patterns are not sufficient to prescribe how much sleep is appropriate. Many have sleep apnea which influences waking up after a number of hours of sleep.

I'm just wondering who in their right mind allows a smart phone receiving email or texts to disturb their sleep? What is it doing in the room with you in the first place? And if you live in a studio apt, there are options known as power button, mute button, airplane mode . . . Hello?

This is an interesting and helpful article to those of us who struggle for a conventional eight-hours of sleep. An additionally helpful article providing insight into cultural differences in sleep patterns by New England Journal of Medicine contributor and sleep expert Dr. Robert Sack entitled "Normal Sleep" is online at ---------------------------http://www.open-spaces.com/article-v4n4-sack.php .

A couple of years ago our power was out for five days as a result of tornados in North Alabama. No lights, no computer, no cellphone service, no television (not a single luxury!). During those days I got the best sleep I have had since I was a child. We fell asleep when it got dark and woke up before it was light, and felt luxuriously rested. This is just an anecdote from which I can draw no scientific inferences.

The "sleep a few hours-wake a few hours-sleep a few hours" routine has only hit me since I turned 60. While I'm up from 2 am to 6 am, I jot down ideas, pay bills online, read, or answer email correspondence. I am fine the next day. I hear the same story from many of my friends. I wondered why Mr. Randall made no mention of the effects of aging on sleep cycles.

There are so many problems with this article it is hard to know where to begin in pointing them out. First, we are not told what the "firste sleep" and "second sleep" of Chaucer, et al. refer to. It is quite possible that one refers to something like a conventional eight-hour sleep through the night and that the other refers to a mid-morning or mid-afternoon nap. So it is entirely possible that people used to get MORE than eight hours of sleep a day rather than less. Also, the efficacy of naps is not directly linked to how much people are sleeping otherwise. An exhausted person suffering from chronic sleep deprivation will more than likely think better after he/she has had a nap than before. The same may also be true, however, of someone who has gotten eight hours, or more of uninterrupted sleep. Basically, this article offers no evidence whatever to support the inference that we don't need eight hours of uninterrupted sleep. It suggests, in fact, only that we appear to function better the more sleep we get.

So where do the insane schedules worked by hospital staff fit into all this? What is the efficiency of an emergency room doctor during his 36th straight hour? And, more importantly, when are hospitals going to wake up (no pun intended) and change their schedules?

Sleep has always been my enemy. For as far back as I can remember I hated to go to sleep. I recall the endless nights of my childhood, laying in bed in the dark totally awake and bored out of my mind. Of course my imagination ran wild in that dark room as I thought about whatever 7 or 8 year old boys think about in the dark.

There was a time during puberty that dreams were my friends. But the older I became and the more I experienced the unpleasantness of adult life my dreams turned on me. During the years I drank too much I rarely remembered dreams upon waking. During a period of depression following the loss of my first wife I developed reoccurring nightmares. Giant maggots would come out of the walls. I'd find scooped-out cat heads on my elbows and knees. One morning I found myself 40 feet out in my front yard crawling naked, trying to escape the white maggots. I got professional help and things got better.

I've only ever gotten about 6 hours sleep per night and if that has harmed me, I can't tell it. In my 30s I decided it was pretty dumb to spend all day awake and on guard and then lay down and become unconscious & totally vulnerable for hours at a time. If modern life is so scary, how do we open the gates, let down the fences for hours each night? The bad guys know everyone goes to sleep at night. Why not rob & rape then?

I lead a normal life despite my lifelong messed up sleep, but my dreams tell me I'm Charles Manson when I'm unconscious...yikes!

When I entered college as a freshman years ago, they told us that we would learn many things besides the content of the courses. And sure enough, in 8:30 AM chemistry lecture, I learned the knack of falling asleep anywhere, any time. This skill has served me well in adult life and I heartily recommend it.

I'd like to know a lot more about how people in other cultures sleep -- especially those cultures that are relatively unaffected by modern civilization. That should be a strong clue as to what is natural, what kind of sleep humans evolved to have.

It's well-known that light impinging on the retina, even through closed eyelids, can be a major influence on how long we sleep. So it seems likely that modern artificial lighting plays a significant role in disrupting our natural sleep patterns.

What is natural for us, of course, probably depends on a number of factors including our individual genetic heritage, the length of daylight, and the weather.

(The late) Buckminster Fuller, the great inventor and 'thinker outside the box' and creator of the geodomic (sp?) dome commented that he slept for one hour each six hours. The total was four hours per day. And, he said he felt well rested and was active for 20 rather than 16 hours daily.

I get impatient with these well-meaning opinion pieces when they attempt to clarify a complex subject matter, then perpetrate new misinformation in place of the old conventional wisdom.

Mr. Randall you lost me after you wrote this: "Some of the time we spend tossing and turning may even result from misconceptions about sleep and our bodily needs: in fact neither our bodies nor our brains are built for the roughly one-third of our lives that we spend in bed."

This is simply nonsense. You apparently believe that today's scientists, and you, by extension, know how to design a body and mind that sleep better than the bodies and minds we have now, which were arrived at after hundreds of thousands of years of genetic evolution. These scientists don't even know what sleep is for, and neither do you. It serves multiple functions, the deepest of which we do not understand. How come a person will first go insane, then die after repeated, long-term sleep deprivation? We don't know the answer to this simple question.

As for the social parameters around getting a decent sleep, most humans simply can't afford the luxury of sleeping whenever and wherever we want to. This was true before the Industrial Revolution when farmers and their helpers had to harvest crops when they were ripe, and it was even more true when workers were turned into machine operators and attendants for factories running at top speed. For ordinary people, this truth will not change, Ambien be damned.

Since my 30s, I've not gotten more than about six hours. Sometimes a little less, sometimes a little more. I've never felt sleep-deprived or guilty about the fact that I don't rack up eight hours a night. I like to sleep, but I like being awake more.

During my time as a wage slave, I got the six hours I seemed to need, 12 midnight to 6 a.m., mostly, with only minimal interruptions. Almost as soon as I retired, my body asserted its own sleep requirements pretty quickly, and two patterns emerged. Pattern No. 1 is the more frequent.

1. Turn in at 10 p.m., awake at 2 or 3, stay up till about 5 or 6, and start the day at 8 or 9.
2. Fall asleep at around 2-3 a.m. and start the day at 8 or 9.

I count myself fortunate to be able to fall asleep quickly. If I feel inclined to nap during the day, I don't hesitate. Naps seem to have minimal effect on the patterns described above.

When this article is linked, the sub-title reads "It's not the quantity of sleep that restores and refreshes, but the quality". This is inaccurate. Dr. Wehr's study observed participants still sleeping 8 hours a night, however these 8 hours were separated into a 5 hour "first sleep" block and a 3 hour "second sleep" block. This suggests that adequate sleep is dependent on both quality and quantity.

Most people do not need 8 hours sleep. Data from millions of people studied by the American Cancer Society and others show that people who say they usually sleep about 7 hours live the longest. In Japan, optimal survival is associated with sleeping 5 to 7 hours. Since brain-wave-recorded sleep tends to be about 1 hour less, optimal survival is seen in 5-6.5 hours sleep, so far as we can estimate.

Therefore, if you are not too sleepy in the day, do not worry about sleeping only 5 or 6 hours at night. One of the main causes of insomnia is lying in bed for 8 hours when you really only need to be in bed for perhaps 6 or 7 hours.

My guess is that sleep needs differ from person to person. I never sleep straight through the night, and always feel the need to sleep come early afternoon. Maybe if I slept when my body wanted to, I'd get a good 4-6 hours at night, and another solid couple of hours in the afternoon, and then perhaps I wouldn't be going around tired all the time.

I'd be interested to see how productive and successful a company might be if they structured the work day based upon the sleep needs of their employees. I'm pretty worthless for about a quarter of the day when forced to sit at a desk while my body wants to sleep.

I'm not sure what the point of this article is, other than to advertise the book. Is he saying that, if your work prevents you from getting 8 hours of sleep straight, that should be ok, as long as you can make it up with a nap later? That kind of job probably doesn't allow for a nap. It's true that there are different ways to achieve sleep, based on culture and individual physiology. It's nice that some people can sleep fewer than 8 hours, or in an interrupted fashion, or have a short nap, and feel revived and productive. It's nice that they are pleased with themselves. Those of us who suffer from sleep problems know that there is no simple answer to insomnia. To butcher Tolstoy "All happy [sleepers] are alike; each unhappy [sleeper] is unhappy in its own way."